diff options
Diffstat (limited to 'prototypes/connections/module-text.c')
| -rw-r--r-- | prototypes/connections/module-text.c | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/prototypes/connections/module-text.c b/prototypes/connections/module-text.c deleted file mode 100644 index 68c03b0..0000000 --- a/prototypes/connections/module-text.c +++ /dev/null @@ -1,189 +0,0 @@ -#include "module-text.h" -#include <math.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> - -enum { CHUNK = 4096 }; - -/* state: pending continuation bytes (bits 0-1) and the allowed range of the - * next one (bits 2-4): 0 any, 1 A0-BF after E0, 2 80-9F after ED, 3 90-BF - * after F0, 4 80-8F after F4. */ -bool pure_utf8_step(unsigned *state, PureSpan span) { - unsigned remaining = *state & 3, range = *state >> 2; - for (size_t i = 0; i < span.size; ++i) { - /* Eight ASCII bytes at a time between characters. */ - uint64_t word; - while (!remaining && span.size - i >= 8 && (memcpy(&word, span.data + i, 8), !(word & UINT64_C(0x8080808080808080)))) - i += 8; - if (i == span.size) break; - unsigned char b = span.data[i]; - if (remaining) { - unsigned low = range == 1 ? 0xA0 : range == 3 ? 0x90 : 0x80; - unsigned high = range == 2 ? 0x9F : range == 4 ? 0x8F : 0xBF; - if (b < low || b > high) return false; - --remaining; - range = 0; - } else if (b < 0x80) { - continue; - } else if (b >= 0xC2 && b <= 0xDF) { - remaining = 1; - } else if (b >= 0xE0 && b <= 0xEF) { - remaining = 2; - range = b == 0xE0 ? 1 : b == 0xED ? 2 : 0; - } else if (b >= 0xF0 && b <= 0xF4) { - remaining = 3; - range = b == 0xF0 ? 3 : b == 0xF4 ? 4 : 0; - } else return false; - } - *state = remaining | range << 2; - return true; -} - -bool pure_utf8_complete(unsigned state) { return (state & 3) == 0; } - -bool pure_utf8_valid(PureSpan span) { - unsigned state = 0; - return pure_utf8_step(&state, span) && pure_utf8_complete(state); -} - -size_t pure_utf8_scalars(PureSpan span) { - size_t count = 0; - for (size_t i = 0; i < span.size; ++i) count += (span.data[i] & 0xC0) != 0x80; - return count; -} - -size_t pure_utf8_newlines(PureSpan span) { - size_t count = 0; - for (size_t i = 0; i < span.size; ++i) count += span.data[i] == '\n'; - return count; -} - -size_t pure_format_number(double value, char out[32]) { - if (value == 0) { memcpy(out, "0", 2); return 1; } - if (value == floor(value) && fabs(value) < 1e15) { - /* An integer's digits, without printf (the common case, many times cheaper). */ - char digits[16]; - uint64_t n = (uint64_t)fabs(value); - size_t count = 0, length = 0; - do { digits[count++] = (char)('0' + n % 10); n /= 10; } while (n); - if (value < 0) out[length++] = '-'; - while (count) out[length++] = digits[--count]; - out[length] = 0; - return length; - } - for (int precision = 1; precision <= 17; ++precision) { - snprintf(out, 32, "%.*g", precision, value); - if (strtod(out, NULL) == value) break; - } - char *exponent = strchr(out, 'e'); - if (exponent) { - char *digits = exponent + 2; /* after the sign */ - while (digits[0] == '0' && digits[1]) memmove(digits, digits + 1, strlen(digits)); - } - return strlen(out); -} - -typedef struct { unsigned char *out; } Copy; - -static bool copy(void *context, PureSpan span) { - Copy *c = context; - memcpy(c->out, span.data, span.size); - c->out += span.size; - return true; -} - -static void read_bytes(const PureDraft *draft, PureVersion version, size_t offset, size_t length, - unsigned char *out) { - Copy c = {out}; - if (length) pure_draft_read_version(draft, version, offset, length, copy, &c); -} - -static size_t forward(const PureDraft *draft, PureVersion version, size_t position) { - if (position >= version.bytes) return version.bytes; - unsigned char lead; - read_bytes(draft, version, position, 1, &lead); - size_t length = lead < 0x80 ? 1 : lead < 0xE0 ? 2 : lead < 0xF0 ? 3 : 4; - return position + length <= version.bytes ? position + length : version.bytes; -} - -static size_t backward(const PureDraft *draft, PureVersion version, size_t position) { - if (!position) return 0; - size_t take = position < 4 ? position : 4; - unsigned char bytes[4]; - read_bytes(draft, version, position - take, take, bytes); - size_t at = take - 1; - while (at && (bytes[at] & 0xC0) == 0x80) --at; - return position - take + at; -} - -/* Saturating: stops at the start or end, so work is bounded by the text size. */ -size_t pure_text_step(const PureDraft *draft, PureVersion version, size_t position, double count) { - for (; count > 0 && position < version.bytes; --count) position = forward(draft, version, position); - for (; count < 0 && position > 0; ++count) position = backward(draft, version, position); - return position; -} - -size_t pure_text_line_start(const PureDraft *draft, PureVersion version, size_t position) { - unsigned char chunk[CHUNK]; - while (position) { - size_t take = position < CHUNK ? position : CHUNK; - read_bytes(draft, version, position - take, take, chunk); - for (size_t i = take; i-- > 0;) - if (chunk[i] == '\n') return position - take + i + 1; - position -= take; - } - return 0; -} - -size_t pure_text_line_end(const PureDraft *draft, PureVersion version, size_t position) { - unsigned char chunk[CHUNK]; - while (position < version.bytes) { - size_t take = version.bytes - position < CHUNK ? version.bytes - position : CHUNK; - read_bytes(draft, version, position, take, chunk); - for (size_t i = 0; i < take; ++i) - if (chunk[i] == '\n') return position + i; - position += take; - } - return version.bytes; -} - -static size_t advance_within(const PureDraft *draft, PureVersion version, size_t position, - size_t columns, size_t limit) { - for (; columns && position < limit; --columns) position = forward(draft, version, position); - return position < limit ? position : limit; -} - -/* Moves keep the column; with no further line the cursor goes to the end or - * the start of the text. */ -size_t pure_text_line_step(const PureDraft *draft, PureVersion version, size_t position, double count) { - size_t start = pure_text_line_start(draft, version, position), column = 0; - for (size_t at = start; at < position; at = forward(draft, version, at)) ++column; - for (; count > 0; --count) { - size_t end = pure_text_line_end(draft, version, position); - if (end == version.bytes) return version.bytes; - size_t next = end + 1; - position = advance_within(draft, version, next, column, pure_text_line_end(draft, version, next)); - } - for (; count < 0; ++count) { - size_t here = pure_text_line_start(draft, version, position); - if (!here) return 0; - size_t previous = pure_text_line_start(draft, version, here - 1); - position = advance_within(draft, version, previous, column, here - 1); - } - return position; -} - -typedef struct { size_t count; unsigned unit; } Count; - -static bool count_span(void *context, PureSpan span) { - Count *c = context; - c->count += c->unit ? pure_utf8_newlines(span) : pure_utf8_scalars(span); - return true; -} - -size_t pure_text_count(const PureDraft *draft, PureVersion version, size_t position, unsigned unit) { - Count c = {0, unit}; - if (position) pure_draft_read_version(draft, version, 0, position, count_span, &c); - return c.count + (unit ? 1 : 0); -} |
